Multi-drawing frame particularly adapted for use on high-speed spinning frames



28, 1959 A. GARDELLA ET AL 2,896,269

MULTIDRAWING FRAME PARTICULARLY ADAPTE'D FOR USE ON HIGH-SPEED SPINNING FRAMES Filed Jan. 15, 1954 2 Sheets-Sheet 1 ATTORNEYQS,

' INVENTORS:

28, 1959 A. GARDELLA ET AL 2,896,269

MULTI-DRAWING FRAME PARTICULARLY ADAPTED OR USE ON HIGH-SPEED SPINNING FRAMES 2 Sheets-Sheet 2 Filed Jan. 15, 1954 1NVENTOR5 ATTORNEYS,

MULTI-DRAWING PARTICULARLY ADAPTED FOR USE ON HIGH-SPEED SPIN- NING FRAMES Adriano Gar-delta and Costantino Gardella, Genoa, Italy Application January 15, 1954, Serial No. 404,342 Claims priority, application Italy January 19, 1953 4 Claims. (Cl. 19--131) Thisinvention relates to a multiple-step high-attenuation high-speed drawing frame particularly adapted for use on high-speed spinning frames for long and coarse fibres such as hemp, flax, jute, ramie and the like and which will be referred to briefly as multi-drawing frame.

The drawing frames of known spinning frames comprise usually a simple draw head constituted of a single inletor feed-roller pair and of a delivery roller pair spaced from the feed roller pair, whereby between these roller pairs guide-and blending means, usually comprising roller and/or belt pairs, are provided.

High-speed spinning frames are also known, provided with Single draw heads permitting of obtaining in a single drawing step drawing ratios up to 1:50 and over, thus feeding into the drawing frame a corresponding heavy sliver. The high attenuation of a sliver in a single step presents however the drawback that the sliver often breaks during drawing and even if it does not break, the attenuated sliver fed into the drawing frame is highly irregular. In order to avoid this, usually pre-attenuated slivers are fed, and in order to obtain highly regular preattenuated slivers, these are obtained by a doubling this term being employed in the meaning of multiplying by any number the slivers after their attenuation, so that the weakest spots of one of the slivers come to be juxtaposed to the thickest spots of at least another sliver, thus giving, as a final result, an attenuation sliver of substantially equal thickness throughout its length.

In the usual pre-drawing frames the doubling was effected by feeding a number of slivers in parallel to a set of roller pairs arranged in series and running at increasing peripheral speeds and then to unite and blend the attenuated slivers together in correspondence of, or shortly before, the delivery end of the drawing frame. By this means however the sliver delivered was not sufficiently homogeneous and furthermore the arrangement was not adapted for receiving heavy card slivers and delivering highly attenuated very homogeneous slivers directly to the spinning frame.

The multi-drawing frame according to the invention eliminates the above drawbacks and comprises a number of draw head sets arranged in parallel-series and decreasing in number from the first set towards the last draw head, which is single, whereby each draw head comprises in a known manner a feed roller pair, a delivery roller pair and possibly means for guiding and blending the slivers being drawn therebetween, the whole being so arranged that a plurality of slivers, each fed to a separate parallel draw head of the first set, by being drawn first separately in the first drawing step and subsequently doubled and drawn in doubled condition at least once, in a subsequent step or in subsequent successive steps, are delivered by the single draw head performing the last doubling and drawing step at the end of the multi-drawing frame, in the form of a highly attenuated homogeneous sliver adapted to be directly fed to the spinning frame.

2,896,269 Patented July 28, 1959 According to a preferred embodiment of the invention at least two draw heads of each drawing step converge towards a single draw head of the subsequent step.

Other objects and advantages will be apparent from the following specification, reference being made to the attached drawings in which:

Fig. 1 shows in elevation part of a high-speed spinning frame provided with a multi-drawing frame according to the invention.

Fig. 2 shows in perspective view another embodiment B arranged in fan formation on the frame 1 and converging towards a single final draw head A. Each single draw head A and B comprises a pair of feedand sliverholding rollers 2, 3 and 102, 103 and a pair of sliver delivery rollers 4, 5 and 104, 105. One of the rollers of each pair is positively drive'n, while the other one is idle.

For all the primary draw heads B a single common pair of delivery rollers 104, 105 is provided, one of said rollers being driven at such a speed as to run with its periphery at a speed that is a multiple of that of the feed rollers. Between the two roller pairs of each draw head A and B, means for controlling the slivers during the drawing are arranged, which, in the example as shown, comprise a pair of endless belts 6 and 7 running respectively on rollers 106, 206 and 107, 207. The construction of said draw heads is alike and is better shown in the enlcrged View of draw head A illustrated in Fig. 3. The plane passing through the axes of the upper rollers 106 and 107 is perpendicular to the path of the sliver being drawn while the plane passing through the axes of lower rollers 206 and 207 is inclined with respect to the said sliver path. The two contacting runs of belts 6 and 7 are pressed against each other by suitable means and include between them the drawn sliver, which they guide and in part brake and blend. In the example as shown said pressing means comprise a leaf spring 8 for each belt run, having a bent end portion attached to the rigid part 9 of the frame, while its opposite end is free to swing towards or away from the sliver-compressing belt runs. A fixed suitably shaped sliver guide 10, inserted between the delivery ends of belts 6 and 7 and the delivery roller pair 4, 5 and 104, 105, provides for a further sliver control.

One of the rollers of the feed roller pairs, of the delivery roller pairs and of the belt guides is positively driven. This is indicated by the arrows F, F1 and F2 in Figure 3. In this figure roller 2 is operatively connected to roller 106 by means of gear pair 302, 306.

The above described drawing and spinning frame operates as follows:

The four primary draw heads B are fed in parallel each with like heavy slivers N1, N2, N3, N4 which are drawn by draw units B independently to a like intermediate size. The said four pro-drawn slivers are subsequently fed up, superposed, into the roller pair 104, 105 and form a single sliver N which in its turn is passed through the draw head A arranged in series to all four draw heads B and from which it is drawn to the required size and comes out of the drawing frame as a highly attenu- 3 ated sliver N which, by being delivered at a speed of the order of the feed speed of the spinning unit is directly fed to the tubular inlet thread guide 11 thereof.

Thus if theslivers drawn in the primary draw heads B are adjusted to .a drawing ratio of 1:20 and if draw head A is adjusted to a drawing ratio of 1:30, assuming that it is desired to obtain a thread weighing 0.4 gr. to the metre, it is sufiicient to feed into the spinning frame four slivers N1, N2, N3, N4 weighing each 60 gr. to the metre, which is in the order of the weight of the slivers as they may be obtained directly from a carding machine, and which therefore may be directly fed in the combined multi-drawing and spinning frame.

The above mentioned numerical result obtained by the parallel-series high attenuation in the above multiedrawing frame may be summarized by the following equation: 60:20X4:30:0.4, the total drawing ratio being of 1:150.

Different total drawing ratios may be obtained either- (I) by varying the drawing ratios at each drawing step and/or (2) by varying the number of primary slivers, and/or (3) by inserting one or even two intermediate drawing steps betweenthe first and the last drawing step.

By the method mentioned under (1) it is usually possible to attain only slight variations, for a given kind of fibre, as there exists for each fibre and size of fed sliver an optimum range of drawing values.

By the method mentioned under (2) it is possible to reduce or increase the size of the completely drawn sliver by fractions having as denominator the number n of primary parallel draw units and as numerator a number ranging from 1 to n-2. Thus by means of the described drawing frame, by feeding a sliver weighing 60 gr. to the metre it is possible to produce slivers N0 weighing 0.4, 0.3, or 0.2 gr. to the metre. Of course, by operating on the same kind of fibrous material, the sliver weighing 0.4 gr. will be usually more homogeneous than those weighing less.

The method mentioned under (3) will be adopted only when very high attenuations and very homogeneous final slivers are desired. A drawing frame embodying this method is diagrammatically shown in Figure 4. This consists of a set of parallel primary draw heads B which deliver an equal number of drawn slivers to each of a set of parallel intermediate draw heads I which in their turn deliver the attenuated doubled slivers to a single final draw head A. In some particular cases it is also possible to arrange two intermediate sets of draw heads.

By the combination of any two of or all said three methods it is possible to obtain all possible sliver attenuations and a final sliver speed as desired.

The draw heads arranged in parallel before the last draw head A are usually arranged as converging towards the subsequent roller pair which provide for the doubling of two or more slivers. If the parallel draw heads of each set are more than two, the arrangement along the corners of a pyramid is preferred, as shown in Figure 2 for the four primary draw heads B which converge towards a single final draw head A, whereby the roller pair 2, 3 constitutes the delivery roller pair of all primary units B and the holding roller pair of the final draw head A.

Generally, it may be said that the delivery ends of the parallel draw heads are arranged at equal distance from the inlet or feed end of the doubling draw head of the subsequent step.

Of course the improved multi-drawing frame may. undergo numerous changes in its construction and arrangement, which may take place even independently of a spinning frame. Furthermore, although in the practical working of coarse fibres the described belt guide arrangement has given the best results, it is to be understood that instead of these other blending and braking guide means may be adopted, such as sets of idle roller pairs or of gills.

We claim:

l. A multi-drawing frame for textile fibre slivers in which the sliver drawing is effected in a number of successive drawing and doubling steps, and comprising a sliver drawing and doubling frame composed of a plurality of primary sliver-feed guides, a primary sliver-draw head for each of said sliver guides arranged to draw its slivers from one of the correspondingly positioned guides, each of said draw heads comprising a feed roller pair composed of two substantially contacting rollers providing a series of feed roller pairs arcuately arranged, means for driving said roller pairs with such a speed as to pull continuously said slivers at the desired feed speed, said primary feed roller pairs being arranged with their substantially contacting lines at substantially equal distances from a common point, a pair of contacting sliverdoubling and delivery rollers driven at a peripheral speed that is a multiple of said primary feed roller pairs arranged with their contacting line passing through said common point, endless belt feed means for guiding the sliver fed by the said primary feed rollers towards the contacting point of said primary sliver-doubling and delivery rollers; said endless belt feed means being disposed at an acute angle one to the other, a pair of substantially contacting secondary sliver feed rollers spaced from said primary sliver-doubling and delivery rollers and arranged so as to receive the double sliver delivered from said primary delivery rollers, said secondary feed rollers being driven at a speed in the order of, but not less than, that of said primary delivery rollers, a pair of secondary delivery contacting rollers arranged in spaced relation and substantially parallel to said secondary feed rollers and driven at a speed that is multiple of that of the said secondary feed rollers and means for guiding the sliver delivered from said secondary feed rollers towards the contacting line of said secondary delivery rollers and means for taking up the sliver issuing from said secondary delivery rollers.

2. A multi-drawing frame for textile fibre slivers in which the sliver drawing is effected in a number of successive drawing and doubling steps, and comprising a plurality of primary sliver-drawing and doubling frames, each of which comprises a plurality of primary sliverfeed guides, a primary sliver-draw head for each of said sliver guides, each 'of said draw heads comprising a feed roller pair composed of two substantially contacting rollers with each feed roller pair arranged to draw its sliver from one of the correspondingly positioned feed guides, means for driving said roller pairs with such a speed as 'to pull continuously said slivers at the desired feed speed which is equal for all the slivers, said primary feed roller pairs being arranged with a point of their substantially contacting lines at equal distances from a common point, a pair of contacting sliver-doubling and delivery rollers driven at a peripheral speed that is a multiple of said primary feed roller pairs, arranged with their contacting linepassing through said common point, a series of endless belt feed means for guiding the sliver fedby each of the said primary feed rollers towards the contacting point of said primary sliver-doubling and delivery rollers; 21 pair of substantially contacting secondary sliver feed rollers corresponding in number to and closely spaced from said primary sliver-doubling and delivery rollers and arranged so as to receive the doubled sliver delivered from said primary delivery rollers, said secondary feed rollers being driven at a speed in the order of, but not less than, that of said primary delivery rollers, a pair of secondary delivery contacting rollers arranged in spaced relation and substantially parallel to said secondary feed rollers and driven at a speed that is a multiple of that of the said secondary feed rollers and means for guiding the sliver delivered from said secondary feed rollers towards the contacting line of said secondary delivery rollers, the secondary delivery roller pairs of each of said primary sliver-drawingand doubling frames being in their turn arranged with a point of their contacting line at equal distances from a common point, a tertiary sliver-doubling and drawing head arranged to receive its slivers from said secondary delivery rollers having a feed roller pair, running at a peripheral speed that is not less than that of the secondary delivery roller pairs, means for guiding all the slivers issuing from said secondary delivery roller pairs between said tertiary draw head feed rollers, a tertiary delivery roller pair running at a speed that is multiple of that of the corresponding feed roller pair, spaced from said last-named roller pair, sliver-guide means between said last-named roller pairs and means for further working the sliver issuing from said tertiary delivery rollers, said series of endless belt feed means including co-acting sets of endless sliver feed belts with the feed belts of each set extending at an acute angle to adjacent sets of feed belts.

3. A multi-drawing frame according to claim 1, in which between the feed and the delivery end of a number of said draw heads, and at least one of said draw heads performing one of said drawing steps comprises a pair of parallel endless belts each fitted on a roller pair, and having their inner runs pressed against each other by spring means.

4. A multi-drawing frame according to claim 1, in

which between the (feed and the delivery end of a number of said draw heads, and at least one of said draw heads performing one of said drawing steps comprises a pair of parallel endless belts each fitted on a roller pair, and having their inner runs pressed against each other by spring means, and in which the said spring means for pressing the inner runs of the belts against each other comprise a leaf spring having a straight body and a curved end attached to a fixed part of the draw head between the belt runs and having its straight body freely swinging against the inner side of an adjacent belt run;

References Cited in the file of this patent UNITED STATES PATENTS 1,559,281 Rushton Oct. 27, 1925 1,905,268 Cotchett Apr. 25, 1933 2,410,020 De Lathauwer Oct. 29, 1946 2,645,822 Cabana -t. July 21, 1953 2,728,112 Berker Dec. 27, 1955 FOREIGN PATENTS 16,297 Great Britain ..of 1898 514,519 Great Britain Nov. 10, 1939 

